Pig DNA points to new path for Pacific islanders

March 17, 2007|By Thomas H. Maugh II

A new study of DNA from pigs is rewriting the history of human migration throughout the Pacific, indicating that most island residents in the region had their origin in Vietnam. Studies of pots and other cultural artifacts previously had suggested that the Polynesian and Oceanic cultures originated in Taiwan and spread rapidly through the Pacific, an idea often called the Express Train or Speedboat Out of Taiwan. To shed light on this period, a large international team headed by archeologist Keith Dobney of Durham University in England studied mitochondrial DNA from 781 modern and ancient pigs. The older specimens were obtained from museums and similar sources. ''Pigs are good swimmers but not good enough to reach Hawaii,'' said archeologist Greger Larson of Uppsala University in Sweden, lead author of the study in this week's issue of the Proceedings of the National Academy of Sciences. ''Given the distances between islands, pigs must have been transported and are thus excellent proxies of human movement.'' They found that a single genetic heritage is shared by the modern Vietnamese wild boar; modern feral pigs on the islands of Sumatra, Java and New Guinea; ancient pigs in Near Oceania, and ancient and modern domestic pigs on several Pacific islands. Significantly, the genetic signature is not found in Taiwan. The team said this indicates that the islanders' ancestors - known as the Lapita culture - left Vietnam about 3,600 years ago and traveled through numerous islands before first reaching New Guinea and, later, Hawaii and French Polynesia.